Urea transporter 1 (SLC14A1)

Urea channel that facilitates transmembrane urea transport down a concentration gradient. A constriction of the transmembrane channel functions as selectivity filter through which urea is expected to pass in dehydrated form.

The rate of urea conduction is increased by hypotonic stress. Plays an important role in the kidney medulla collecting ducts, where it enables rapid equilibration between the lumen of the ducts and the interstitium, and thus prevents water loss driven by the high concentration of urea in the urine.